尝试从SQL返回true或false

Question

Here is my code:

$result_username = mysqli_query($dbconnection, Data::checkForUsername($username));

It then goes here:

   public static function checkForUsername($username) {
            global $database;

            $query = "
                SELECT COUNT(*) 
                FROM users 
                WHERE username='{$username}';";

            $result = $database -> query($query);

            return $result;
        }

Then $result does this:

if (mysqli_result($result_username, 0) > 0) {

However, it then gives me back a Resource_Id?? I can not figure out why?

I simply want to check if the username exists in at least 1 row.

Answer 1

You need to fetch your data after you execute your query

$row = $result->fetch_array(MYSQLI_NUM);
return $row[0];

UPDATE: Now, using prepared statement your function can look like this:

public static function checkForUsername($username) {
    global $database;

    $result = 0;
    $query = "SELECT COUNT(*) FROM users WHERE username=?";
    /* create a prepared statement */
    if ($stmt = $database->prepare($query)) {
        /* bind parameters for markers */
        $stmt->bind_param("s", $username);
        /* execute query */
        $stmt->execute();
        /* bind result variable */
        $stmt->bind_result($result);
        /* fetch value */
        $stmt->fetch();
        /* close statement */
        $stmt->close();
    }
    return $result;
}

Answer 2

You can try

return $result->num_rows

Then

if (checkForUsername('Redeyes') != 0) {
}